Matthew of Electronics for Humans has been working on 3D printer controller:
The design is based on an Atmel Atmega328 running at 8MHz (using the internal clock) at 3.3V. This is in order to keep the same voltage as the main controller board, which will be powered by the LPC1768 that only works at 3.3V or thereabouts. Furthermore, I am intending to use the Arduino Bootloader (at least at first) and the Arduino platform in general to program it. The reasons for this choice will be explained later.
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